862 S.A. MEDICAL JOURNAL 10 October 1959 Fig. 7. Cycle of normal mitral-valve movements showing the opening and subsequent closure. order to avoid the presence of bubbles or a receding water system enables one to study and photograph the action of meniscus, which may impair visibility. The action of the normal and abnormal valves and also to study and test valve can be carefully observed and photographed through prosthetic valves under conditions of pressure and volume the top chamber (Fig. 7). flow similar to those existing in the normal circulation. CONCLUSION We are most grateful to the United States Public Health Depart­ The use of the artificial pulse duplicator makes it possible ment, the South African Council for Scientific and Industrial to study the action of normal and abnormal aortic and mitral Research, and the University of Cape Town Research Grants, for valves under conditions of pressure and flow similar to those valuable financial assistance. We should also like to thank Mr. C. present in the beating heart. Intrinsic valvular action, however, C. Goosen, technician to the Department of Surgery, University cannot be evaluated in such a system, but despite these of Cape Town, for the photography of diagrams and figures included in this article, and Mr. J. Linney, representative of disadvantages the apparatus has proved to be of great value Messrs. A. Lalieu (Pty.) Ltd., for making a film of the opening for the study of the action of prostheses designed to correct and closing of the valve, from which we have taken Fig. 7. incompetent valves, and, in addition, such a system may be used to test the durability of a prosthesis under conditions REFERE CES similar to those found during life. I. Melrose, D. G., Dreyer, B., Bentall, H. H. and Baker, J. B. E. (1955): Lancet .. 2,21 . SUMMARY 2. Lam, C. R. (1956): J. Thorac. Surg., 32, 370. 3. Efller, D. B., Groves, K. L., Sones, F. M. and Kollf, M.J.(I956): Cleveland The construction and method of operation of a simple CIin. Quan., 23, 105. 4. Got!, V. L., GonzaIes, J. L., Zulidi, M. N., Varco, R. L. and Lillehei, C. w. inexpensive artificial pulse duplicator is descrIbed. Such a (1957): Surg. Gynec. Obstet., 104,319. THE TUMBU FLY, CORDYLOBIA ANTHROPOPHAGA (BLANCHARD), IN SOUTHER AFRICA* F. ZUMPT, Department ofEntomology, South African Institute for lvledical Research, Johannesburg Cordylobia anthropophaga, the 'Tumbu fly' or 'skin maggot In the Union of South Africa this parasite has become of fly' is widespread over the Ethiopian region, i.e. Africa greater importance only in recent times. Drs. Annie Porter south of the Sahara, but it does not occur in any other zoo­ and Heymann,l who submitted a paper on this fly at a meeting geographical region of the world. In West and Central of the Medical Association in Johannesburg on 19 December Africa it is a very common pest; the larvae affect mainly 1929, 30 years ago, said that 'in the Union of South Africa humans, dogs and various kinds of rats, but they are also such cases are relatively uncommon'. They presented a case occasionally found in other wild and domesticated mammals. of a 9-months-old European girl who had contracted the infection during a short stay in the Bulawayo district, * Paper read at the National Meeting of the Dermatological Sub-group ofthe Venereology and Dermatology Group (M.A.S.A.), S. Rhodesia. Pretoria, 28 March 1959. De Meillon and Gear,2 in 1947, said that the Tumbu 10 Oktober 1959 S.A. TYDSKRIF VIR GENEESKUNDE 863 fly was already very well known in the subtropical regions of Southern Africa, such as the Transvaal Lowveld, Natal and Zululand, but that for the first time specimens from human patients had been sent to the South African Institute for Medical Research from the Transvaal Highveld. There had apparently been a minor epidemic at Witbank, and several locally contracted infections had been found in the environs of Johannesburg, Pretoria, Springs and Lichtenburg. Since then, we have received many more records of human infections with Cordylobia from Southern Africa, and de Meillon and Gear's assumption that the Tumbu fly has continuously enlarged its territory has proved to be true. The distribution of cases is shown in the map in Fig. 1, and in Table I, which includes the reliablet records known to me from our own cards and from the literature. It will be seen that human infection with Cordylobia anthropophaga has occurred widely in the Transvaal and the neighbouring part of the Orange Free State. It must be noted that when larvae TABLE 1. RECORDS OF CORDYLOBIA ANTHROPOPHAGA (BLANCHARD) FROM SOUTHERN AFRICA Locality and Date Stage Host Ondongua, S.W. Africa. VI, 1934 .. L Tatera ioanae (=T. U[ra) Outjo, S.W. Africa. Ill, 1953 L man Fig. 1. Map of Southern Africa showing distribution of Epukiro, S.W. Africa. lll, 1950 LMF ? Cordylobia anthropophaga. Okahandja, S.W. Africa. 1ll,1951 L man Omitara, S.W. Africa L Thallomys nigri­ extracted from humans are sent to us, it is not always certain cauda (= Rattus that the infection has really been contracted in the district paedulcus) Ondekaremba, S. W. Africa L Tatera schinzi where the patient lives, even when he maintains that this is so. (=T. aIra) The larvae may stay in the human for quite a long time, Seronga (Ngamiland), Bechuanaland. VII longer than in their normal hosts, the rats, and the patient 1949 MF ? may have contracted the infection on a trip to the Lowveld' Shamva, S. Rhodesia L man Bulawayo, S. Rhodesia L man or some other subtropical part of Southern Africa (see Messina, Transvaal .. L man below). But for the practitioner this fact is not of such great Pietersburg, Transvaal. 1,1941 L dog importance as for the epidemiologist. The practitioner has Letaba, Transvaal. 1,1915. XII,1916 L man, dog to diagnose and to treat the infection wherever it appears in Thabazirnbi, Transvaal. IV, 1957 .. F ? Nylstroom, Transvaal. HI,1957 .. L man humans, and he should be acquainted with the aetiology and Lydenburg, Transvaal. IlI,1957 " L man pathology of the disease. Rustenburg, Transvaal. XII, 1958 L man Koster, Transvaal. 111,1953 L man LIFE-HISTORY Pretoria, Transvaal (incl. Onderstepoort). I, 1915. XII, 1916. XII, 1939. I, 1944. L man, dog, The adult fly is rarely seen in nature, but it may be found in X, 1948. I, 1949. guinea-pig houses and huts, resting in dark places during the day-time. Witbank, Transvaal .. L man Males and females are very similar to each other, of yellow Lichtenburg, Transvaal L man and dark-brown colouring, and measure 6-12 mm. in length. Environs of Johannesburg (inc!. Sandown, L man Bryanston, Springs, Y okeskei River). XI, They become active In the late afternoon and in the early 1909. III,1949. 1II,1953. morning. At night they rest too, but may be attracted by Klerksdorp, Transvaal. 1,1959 L man artificial light. Stegi, Swaziland. 1,1951 L man The adult fly does not live parasitically, but feeds, like Hoopstad, Orange Free State. 11,1955 L man Viljoenskroon, Orange Free State. 11,1953 L man many other blowflies (fam.: Calliphoridae), on the juices Vredefort, Orange Free State. H, 1958 L man of plants, for instance bananas, pine-apples and other fruits, Harrisrnith, Orange Free State L man and also on decomposing animal substances and on excreta. LoureDl;o Marques, Mozambique. XIl L man For oviposition, the female is especially attracted to dry 1908 Durban, Natal L man sand which has been contaminated with urine or faeces. U the sand is still too moist, eggs are not laid there but are t Not all records in the literature are, of course, reliable. The often deposited near by on a dry spot. Blacklock and late Mr. Bedford (1927), for instance, wrote that he had taken Thompson3 (1923), in theirexcellent study on C. anthropophaga numerous adult flies of C. anthropophaga 'at the entrances of wart-hog burrows' in the Northern Transvaal and in Zululand. in Sierra Leone, reported on an experiment in which wet sand He also said that the larvae parasitize wart-hogs and ant-bears. had been provided for a mature female fly. She landed on Be·dford had confused C. anthropophaga with Auchmeromyia it and protruded the ovipositor, 'but apparently found it too bequaerti Roubaud, which is very common in these areas and the wet', flew off again and deposited about 100 eggs in a plug larvae of which live as blood-suckers on wart-hogs and ant-bears. These two hosts, however, have never been found infected with of pink cotton wool. This observation is important in larvae ofthe true Tumbu fly. respect of human cases, the flies being attracted to, and 864 S.A. MEDICAL JOURNAL 10 October 1959 stImulated for oviposition by, the soiled napkins of babies. The 2nd larval stage arises as the result of a moult which They do not deposit their eggs on the wet clothes, but neaT occurs in the tissues of the host about the 3rd day after by on the dry parts. If these napkins or other soiled clothes penetration. The larva then measures from 2·5 to 4 mm. and are not properly cleaned and ironed (they may appear qulte is quite different in shape. The 3rd and last moult, again in clean to the human eye and nose), the flies may be attracted the tissues, takes place on the 5th or 6th day. The 3rd stage to them, for oviposition, in the same way as to dry cop.tami­ is again different from the 2nd, so that all three stages may nated sand.